Details

An updated kexec-tools package that resolves three security issues, fixes several bugs and adds various enhancements is now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having moderatesecurity impact. Common Vulnerability Scoring System (CVSS) base scores,which give detailed severity ratings, are available for each vulnerabilityfrom the CVE links in the References section.

The kexec-tools package contains the /sbin/kexec binary and utilities that together form the user-space component of the kernel's kexec feature. The /sbin/kexec binary facilitates a new kernel to boot using the kernel's kexec feature either on a normal or a panic reboot. The kexec fastboot mechanism allows booting a Linux kernel from the context of an already running kernel.

Kdump used the SSH (Secure Shell) "StrictHostKeyChecking=no" option whendumping to SSH targets, causing the target kdump server's SSH host key notto be checked. This could make it easier for a man-in-the-middle attackeron the local network to impersonate the kdump SSH target server andpossibly gain access to sensitive information in the vmcore dumps.(CVE-2011-3588)

The mkdumprd utility created initrd files with world-readable permissions.A local user could possibly use this flaw to gain access to sensitive information, such as the private SSH key used to authenticate to a remote server when kdump was configured to dump to an SSH target. (CVE-2011-3589)

The mkdumprd utility included unneeded sensitive files (such as all files from the "/root/.ssh/" directory and the host's private SSH keys) in the resulting initrd. This could lead to an information leak when initrd files were previously created with world-readable permissions. Note: With this update, only the SSH client configuration, known hosts files, and the SSH key configured via the newly introduced sshkey option in "/etc/kdump.conf" are included in the initrd. The default is the key generated when running the "service kdump propagate" command, "/root/.ssh/kdump_id_rsa". (CVE-2011-3590)

Red Hat would like to thank Kevan Carstensen for reporting these issues.

This updated kexec-tools package also includes numerous bug fixes andenhancements. Space precludes documenting all of these changes in thisadvisory. Users are directed to the Red Hat Enterprise Linux 5.8 TechnicalNotes, linked to in the References, for information on the most significantof these changes.

All users of kexec-tools are advised to upgrade to this updated package, which resolves these security issues, fixes these bugs and adds these enhancements.

Solution

Before applying this update, make sure all previously-released erratarelevant to your system have been applied.